We all love mashups – the combination of characters and elements that are not supposed to be together. They don’t happen often, outside of unofficial fan fiction, due to the logistics of copyrights and such. But sometimes there’s an idea that’s so cool it has to be made. One of those ideas was to combine Batman with anime. The result was Batman Ninja, a cooperative project between DC Comics, Warner Brothers Studios and director Junpei Mizusaki and writer Kazuki Nakashima. I couldn’t wait to see if it lived up to its awesome potential.

The premise is that Batman’s enemy Gorilla Grodd creates a time travel machine and tests it on his fellow villains in Arkham Asylum. While trying to stop him, Batman and his superhero sidekicks get caught up in the “time quake,” and end up in one of history’s most interesting historical periods – feudal Japan. Why this particular time and place? Why not?

As the movie opens, an explosion in Arkham Asylum causes the place to disappear. Batman finds himself alone in Japan, and Catwoman appears to explain what has happened. Because Batman was farther away at the moment of transition, he’s been deflected in time, arriving in Japan two years after Grod and the other villains. Batman’s sidekicks, including Robin, Nightwing, and Alfred are there as well.

You may wonder, how can Batman speak Japanese the moment he gets there? It’s because he’s spent years studying martial arts, and besides, he’s Batman. During the two years before his arrival, the villains have set themselves up as feudal lords throughout the country. Joker is most powerful, accompanied by Harley Quinn.

The greatest thing about this show is its superb character design. Joker looks amazing in samurai armor with his green hair bound in tiny braids and is his usual devious self. As much as I liked the Margot Robbie version, the anime girl Harley is her equal in sex appeal. The other villains, except for Grod and Catwoman, play minor roles. Batman’s mission is to capture Grod’s time machine to prevent the bad guys from changing history and to get everyone back to the present.

Many of Batman’s high-tech weapons and vehicles got whisked along with Alfred and company, who have kept them ready for his arrival. It doesn’t take long for these to break or run out of fuel. Batman turns to his skills with swords and shuriken and enlists the help of both Catwoman, the ninjas of the “Bat Clan” and Robin’s army of trained monkeys. (That’s what he’s been doing in the last two years.) Of course, Catwoman betrays Batman – you’d think he’d know by now she can’t be trusted.

Batman Ninja has lots of exciting battles – sword fights, fist fights, fights aboard ship, etc. The movie goes off the rails in the second half when the castles of the supervillains (Joker, Two-Face, Poison Ivy, Bane, and of course Gorilla Grodd) uproot themselves and meet for a battle royale in the shadow of Mount Fuji. In other words, they’re all giant mechs. Ugh! Call me an old fuddy-duddy, but I’ve always thought Gundams and Transformers were for little kids. They’re especially silly in the context of Fourteenth Century technology. Yes, it’s a time travel fantasy based on a comic book, but even my suspension of disbelief has its limits.

The drawback of an ongoing franchise like Batman is there can be no major surprises. Everything has to return to the status quo at the end. Still, it’s a fun ride and I’d recommend it only to hard-core otaku. I deducted a whole star for the moving castles (In my book, only Howl is allowed to do that.) I give it 3.5. You can get Batman Ninja on DVD or Blu-Ray or watch it streaming on-line.